The present invention relates to a new and improved construction of auxiliary apparatus for an optical observation instrument or device, especially for a surgical microscope.
Generally speaking, the auxiliary apparatus is used in conjunction with a stand, at which there is mounted the surgical microscope or other observation instrument. The microscope is arranged at a hinge parallelogram rotatable about a first axis and pivotable about a second axis of a support arm, this second axis being arranged transversely with respect to the first axis. The stand is provided with a number of rotary and brake bearings. The microscope can be freely adjustable, but fixedly positioned, throughout a predetermined spatial region as concerns its position and orientation.
Adjustable supports or stands for optical observation instruments are well known to the art, as evidenced for instance by the commonly assigned U.S. Pat. Nos. 3,762,796, granted Oct. 2, 1973, 3,762,797, granted Oct. 2, 1973, 3,887,267, granted June 3, 1975 and 3,891,301, granted June 24, 1975.
In particular, in Swiss Pat. No. 548,568 and the corresponding U.S. Pat. No. 3,891,301 there is disclosed a support device for a surgical microscope, which is constructed as a stand, wherein for the exchange of different microscopes, or for the mounting of different auxiliary devices at the microscope, for instance for mounting a photographic or television camera, a balancing or compensation weight is displacably arranged upon a support arm of the equipment. This support arm is articulated at the pivotal arm and is oriented essentially horizontally. By means of the balancing or compensation weight it is possible to balance the rotational moment of the suspended microscope. This rotational moment is effective at the relevant rotary and brake bearings and is caused by the weight of the microscope. This measure for compensating the rotational moment by means of the additional compensation weight which, depending upon the size of the microscope and the weight, is cantilevered to a greater extent, is particularly suitable for use with support apparatus of robust or massive construction which are not inhibited by any spatial limitations.